With regard to the technological background and the prior art, reference is made to WO 2012/003004 A2, US 2002/0139956 A1, U.S. Pat. No. 8,647,709 B2, WO 2010/127981 A1, US 2011/0039066 A1, US 2012/0045954 A1, WO 2014/095112 A1 and US 2014/0127516 A1 and US 2012/0244287 A1. The following description is built on the knowledge base of these documents.
Fluid-dynamic bodies, which are operated under atmospheric conditions, as for example in the case of rotor blades of aircrafts or wind power plants or fluid-dynamically active surfaces of aircrafts or the like, are at risk due to the formation of a layer of ice and the deterioration of the fluid-dynamic properties resulting therefrom. It is therefore known to take protective measures for the protection of such fluid-dynamic bodies against the formation of ice. A possible protective measure consists in providing the respective surface areas with an anti-ice coating, which are at risk of developing ice. Most known anti-ice coatings are passive, i.e. they show a certain inherent hydrophobic and ice-phobic property due to a large contact angle and/or a good water drip off behavior. However, a significant disadvantage of these purely passive anti-ice coatings is the relatively high risk of an icing under very cold conditions. Active anti-ice coatings are understood to be coatings, which are capable of delivering an anti-ice agent. Anti-ice agents are substances, compounds, mixtures or batches which have a freezing point lowering property. Such active coatings may avoid an icing also under cold conditions of minus 10° C. and below.
In the prior art, passive anti-ice properties for coatings may be obtained for instance by super hydrophobic polymers—see, for example, US 2012/0045954 A1—or by surface structuring, for instance on the nanoscopic or microscopic level, as shown in WO 2014/095112 A1.
Active anti-ice coatings may be achieved with coatings, which are especially capable of releasing anti-ice liquids—see, for example, US 2012/0244287 A1, U.S. Pat. No. 8,647,709 B2 or US 2002/0139956 A1—or anti-ice proteins—see, for example, WO 2010/127981 A1 or US 2011/00390066 A1.
A further example of an active anti-ice coating is the coating which is commercially available from the company Microphase under the trade name “IcePhob ESL”.
Currently known active anti-ice coatings only show a low erosion resistance and a quick leaching of the active agent, as for example an anti-ice protein or an anti-ice liquid. As a result thereof the lifetime of the coating is very limited and difficult to predict.